A liquid crystal display is a thin flat display device, having a structure mainly including an array substrate, a color filter substrate, and a liquid crystal molecule layer located between the array substrate and the color filter substrate. The array substrate mainly has thin film transistors arranged in an array, data lines and gate lines disposed thereon; and the color filter substrate mainly has a black matrix and a color filter layer disposed thereon. A main function of the black matrix is to shield the thin film transistors, the data lines and the gate lines disposed on the array substrate, so that the liquid crystal display has a good display effect, and therefore the black matrix should have a suitable line width, in order to just completely shield the thin film transistors, the data lines and the gate lines. In addition, in order to achieve a better shielding effect, structures such as the black matrix and the color filter layer may be directly disposed on the array substrate, wherein the black matrix is located above the thin film transistors arranged in an array, the data lines and the gate lines.
The above description indicates that an accurate setting of the line width of the black matrix has a great influence on a display effect of the liquid crystal display. The inventors find that, when an actual exposing process is being performed, there is a certain gap between a mask and the black matrix or the color filter layer substrate, the gap leading to a deviation between the line width of the black matrix or the color filter layer actually fabricated and a line width of a corresponding pattern on the mask used thereby. This deviation leads to inconsistency between the line width of the black matrix actually fabricated and the preset line width, so that the black matrix cannot just completely shield the thin film transistors, the data lines and the gate lines, which worsens the display effect of the liquid crystal display.